[目的] 研究紫穗槐根系在不同含水率和不同融化时间对土体加固作用，为季冻区紫穗槐固土效应提供设计依据。 [方法] 以取自西宁市黄土为研究对象，用室内三轴试验方法研究紫穗槐根系根—土复合体的应力应变及强度特性，探讨在不同解冻时间和不同含水率下紫穗槐根—土复合体抗剪强度指标变化规律，并通过SEM电镜扫描试验从微观的角度评价紫穗槐根系的加固机理。 [结果] 紫穗槐根系在不同含水率时有不同的加筋情况，在低含水率和高含水率加筋作用更加明显；在冻融前后紫穗槐根系的加筋作用体现在当土体受到荷载作用时，紫穗槐根系会束缚土颗粒之间的移动，增大土颗粒之间的咬合以及增大根系和土颗粒之间的接触面，从而增大内摩擦角；通过电镜扫描试验可以看出，紫穗槐根系可以抑制土体中的裂隙产生与发展，从而增大土体的整体性。 [结论] 紫穗槐根系在不同地区均能起到加筋作用。不同含水率会存在不同的最佳含根量，紫穗槐根系的固土作用体现在增大土体的内摩擦角，增加土体的整体性。
[Objective] The reinforcing effects of Sophora japonica roots on soil at different water contents and different thawing times were studied in order to provide a design basis for the soil consolidation effect of Sophora japonica in the monsoon freeze zone. [Methods] The stress-strain and strength characteristics of the root-soil composite of the Sophora japonica root system were determined using the indoor triaxial test method. The shear strength index of the Sophora japonica root-soil composite was determined under different thawing times and different moisture contents. [Results] The reinforcing effect of the Sophora japonica root system at different water contents was most obvious at low and high water contents. The reinforcing effect of the Sophora japonica root system before and after freezing and thawing was reflected in the fact that the Sophora japonica root system bound the movement between soil particles when the soil received a load, increased the occlusion between soil particles, and increased the contact surface between the roots and soil particles, thus increasing the angle of internal friction. The electron microscope scanning test showed that the Sophora japonica root system inhibited the generation and development of cracks in the soil, thus increasing the integrity of the soil. [Conclusion] The Sophora japonica root system can result in a reinforcing effect in all areas. There are different optimal root contents for different water contents. The solidification effect of the Sophora japonica root system is reflected by the increase in internal friction angle of the soil body, increasing the structural integrity of the soil.